Internal-combustion engine.



f United States,

UNITED sTATEs PATENT oEEIeE.

NIA, ASSIGNOR TO THE ,DOCK GAS ENGINE A CORPORATION OF NEW JERSEY.

IN TERNAL-COMBUSTION ENGINE.

ySpecification of Letters Patent.

Patented oct. a2, 1907.

Application filed November 19,1906. 'Serial No. 343,9 49

To all lwhom it may concern: j

Be it known that I, HERMAN Doen, a citizen of the residing at Wyncote, Montgomery county, Pennsylvania, have invented certain new and useful Improvements in InternaLCOmbustion Engines, of which the following is a full, clear, and exact description.

My invention relates to improvements in internal combustion engines and consists in means for controlling the speed of the same. This means is also useful in facilitating the starting of the engine..

In the accompanying drawings: Figure l conventionally illustrates in section a gas engine cylinder with my improvement shown inside elevation. Fig. 2 is a relatively enlarged cross-section View of my invention.

Fig. 3 is a longitudinal section on a smaller scale than shown in Fig. 2. Fig. 44 is a plan view of the-controlling member broken away at the ends.

A conventionally represents the cylinder of an ordinary gas engine of the four-cycle type; the piston, rod,` main-shaft, etc. not being shown.

B represents the usual inlet valve.

D represents the usual outlet or exhaust valve.

E is a regular exhaust cam mounted on shaft F, which may be driven in the usual way from the main engine shaft (not shown). The function of cam E is to open the exhaust valve on every other return or back stroke of the piston. i

G is a supplemental exhaust cam opposite to cam E but in alinement, by which I mean in the same plane therewith. The nose of this cam G is arranged to be projected or retracted at will. The cam G is mounted in a recess in the body-of cam E iu such a manner that it may be drawn entirely back so as to be inactive or projected outwardly in a radial direction to any desired extent within its fullrange of action. It follows from the foregoing that when the cam G is projected outwardly it will operate on the exhaust valve D on the intermediate return strokes of the piston and hence,` since these intermediate return strokes are compression strokes, it follows4 the degree of compression within the cylinder may be modified to any desired extent.' 'For this reason the cam G is useful not only in starting the engine but also Vin -controlling the speed of the engine while running. In starting the engine the cam G would preferably, be projected to its extreme limit so that the minimum compression `would occur. As shown, after the engine has started the ca-m G may be retracted, whereupon the engine will pick up speed..

In the-particular form shown in the drawings the cam- G hastwo rearwardly projecting side arms Gf G/ which form the body or frame ofV the cam G. These arms straddle the shaft F and which serve toguide and steady said cam in its excursion to and iro. These arms are supported by the side walls of the cavity in which the cam is located. Within the shaft F, which is holy low, is a relief cam controlling shaft H, this shaft has a sliding movement to and fro in the hollow cam shaft F and makes a suitable engagement with the supplemental cam G so that by shifting its longitudinal positionl within shaft F the supplemental cam G may be projected to any desiredrextent. As shown, the controlling shaft H is longitudinally recessed, the bottom ofl said recess forming an incline. G2 is a stud or projection on the cam G between theside arms GJ G. The end of said projection G2 passes intoshaft F and is supported upon the incline at the bottom of the recess in the shaft H', hence, when said shaft is moved to and fro the camy 'G will be moved radially.Y One simple and effective means for retracting the cam G may comprise a spring I located between the shaft F and a part of cam G. 'As

shown, the side arms G G are brought together underneath shaft F and` this spring I bears against the same so as to force the cam G backinto its recess in the cam E when the shaft H is retracted. A pin 'I may b e provided to support the spring I, which latter in the particularv form shown is spiral. f

K is the usual lever pivotally mounted at one end,

the other end bearing under the stem of exhaust valve D.'

The usual anti-friction roller L may be provided to` `prevent undue wear on the cams.

One decided Aadvantage of locating the cam G in `alinement with the cam E resides in the fact that there is no necessity for shifting the cam shaft longitudinally in order to relieve the compression. In some instances the valve operating levers are shifted laterally in order to permit a relief cam to-come into operation. but by my improved construction this is avoided. l

Another advantage which results from the locating of the relief cani in alinement with the main cam is that p much space is economized since both cams can be comparatively` narrow. The ease and economy of replacement of the-relief cam in case the same should `become l unduly worn is another advantage resulting from this construction. In the usual construction it is necessary to procure an entirely new main and relief cam where replacement is required since such members are ordinarily made integral.

What I claim is:

1. In an internal combustion engine an exhaust valve controlling meanslincluding a cam shaft a main cam, an. oppositely arranged secondary cam carried thereby and ln alinement therewith and means for projecting and re-- tracting said cam to move it into or out of an operative position said mcansncluding a longitudinally movable inner shaft passing through said secondary cam.

2. In an internal combustion `engine an exhaust valve controlling means including a cam shaft a main cam, an oppositely arranged secondary cam carried thereby and in alinement therewith and means for projecting and retractlio' ing said cam to move it into or out of an operatlveposition andvfor holding the same at an-interxnedlateposition said means including a longitudinally movable inner shaft passing through said secondary cam.

3.. In an internal combustion engine an exhaust valve nontro1lingmeans including a cam shaft a main cam, an oppositely arranged secondary cam carried thereby and in alinement therewith and means'for projecting and retracting said cam `to move it into or ont of :inoperative position and for holding the same at any -intermediate position said means including a longitudinally movable inner shaftpassing .through`said secondary cam to prg. Y

jectl the same,`and a spring to retract the same. n

4 yIn an internalcoinbusti'on engine an exhaust valve controlling means including a main shaft a. lmain cam, an

oppositely arrangedlsecondary cam carried thereby and in tion, said means including a` longitudinally movinginner shaft concentric with the camshaft and operatively connected with the supplemental cam said inner shaft havingA l a longitudinal inclined groove indts face, said secondary cam having a4 projection extendingdntp, said groove and` bearing on the incline thereof. l

HERMA-N DQCK'..

Witnesses:

' R; C. MITCHELL, 

